S64< POLYZOA INFUNDIBULATA. 



scription of the species, he says that he has constantly found the 

 number to be thirty. 



21. Cycloum,* Hassall. 



Character. — " Pol^pidom fiesliy^ encrusting, covered with 

 numerous imperforate jyapiUce. Polypi ascidian ; ova in clus- 

 ters.'''' Hassall. 



1. C. PAPILLOSUM. A. H. Hassall. 



Plate LXX. 



Cycloum papillosum, Hassall in Ann. and Mag. N. Hist. vii. 483. 



Hah. Parasitical on Fucus serratus. 



" This species is almost invariably found investing the frond of 

 Fucus serratus, over the surface of which it spreads in patches of from 

 one to two inches in extent, more frequently of one, and seldom ex- 

 ceeding two inches. The crust is fleshy, and rather thick : it is 

 covered with numerous papillae very closely set together. The po- 

 lypi do not issue from these papillae, which are imperforate, but 

 from larger eminences of irregular form and size, in the centre of 

 which a puckered depression is seen. The polypi have eighteen ten- 

 tacula, describing a cup or bell. * The ova lie in clusters, each clus- 

 ter containing six or seven ova arranged in a circle. The clusters 

 are irregularly scattered through the polypidom, and each is inclosed 

 in a space somewhat larger than is sufficient to contain it, the re- 

 mainder of the space being occupied by a fluid in which numerous 

 small particles are seen, which are kept in constant action by the 

 motion of the cilia on the ova. Each ovum is of a circular form, 

 but is depressed, one side more so than the other : round its edge a 

 fringe of cilia is apparent ; these may be seen in motion long before 

 the ova are ready for becoming disengaged. I have discovered in 

 this, as well as in the succeeding and some other genera, a body of a 

 very peculiar nature, but concerning the uses of which I can at pre- 

 sent only hazard some conjectures. It is, in this species, and in 

 Alcyonidium gelatinosum and hirsutum, in which I have also met 

 with it, of an oblong form, and composed of a transparent matter, in 

 which numerous small dark brown granules, circular in shape and 

 not unlike ova, are imbedded. I at first imagined that they were 

 nothing more than particles of lime lodged in a soft jelly-like sub- 



* From kvkKoq^ a circle, and loov, an egg; in reference to the arrangement of the 

 ova. 



